Wavelength converters are used in particular in flat light sources, such as for example in organic light-emitting diodes (OLED). Appl. Phys. Lett. 80, 3470-3472 (2002) describes an electroluminescent component, in which a mixture of organic and inorganic fluorescent converters and a polymeric matrix material is applied onto the back of a substrate. The material particles or molecules, which are provided as converter material, are dispersed or dissolved in a matrix of a liquid polymeric organic material and then applied as a thin layer onto the back of the substrate. With this type of production it is necessary for the matrix material to be suitable for forming a layer or a thin film; a polymeric organic material is therefore used in this case.